The invention relates to a method for the operation of a driver assistance system of a vehicle, particularly of a motor vehicle and/or a commercial vehicle. The invention also relates to a method for the operation of a communication infrastructure for detecting and producing road traffic data. The invention also relates to a computer of a driver assistance system in a vehicle.
Data which is generated by a vehicle which is actively participating in traffic activity is called floating car data (FCD). Participation by a vehicle in traffic activity includes both the state of driving as well as the state of being stopped, e.g. in a traffic jam, at a light, or in a waiting area. The traffic status message sent by the vehicle to a central computer of at least one communication infrastructure contains at least one time stamp as well as coordinates of the vehicle. The central computer, which is typically managed by an electronic data transmission service provider, receives the preferably anonymized traffic status message from the vehicle. In combination with data from stationary sensors, information contained in the traffic status message is used to deduce a status of traffic activity on certain road segments or in certain traffic segments. A message which describes and/or represents the traffic status, the message optionally also containing information regarding potential deviation opportunities, is transmitted by the central computer to the vehicles. Computers in the vehicles check the received data for plausibility. This means that the computers check the current location utilizing the coordinates thereof and also check a selected route. By using the information contained in the message, the vehicles can compute a route which is suitable for them and which incorporates details of the current traffic activity.
A further development of the floating car data concept is that of extended floating car data (XFCD), wherein additional data from assistance systems built into the car, for example ABS, ASR, ESP, or rain sensors, are incorporated by a computer of a vehicle to determine the content of the traffic status message. XFCD recognizes, for example using ABS and ESP data, that a stretch of road just negotiated has black ice.
In the case of existing or planned communication infrastructures for detecting and producing road traffic data, a traffic status message is transmitted to the central computer if an event is detected by the vehicle, for example the beginning or the end of a traffic jam. The traffic status messages are typically transmitted to the central computer via a mobile communications channel, wherein each transmission of a traffic status message entails costs for the service provider. For this reason, transmission of a traffic status message is discontinued or suppressed as soon as the vehicle receives a message from the central computer of the service provider for the detected event. Until the message about a particular traffic event produced by the central computer is broadcast, all vehicles detecting the traffic event transmit a traffic status message to the central computer. Therefore, for one particular event, in principle a large number of traffic status messages are transmitted to the central computer, resulting in high costs. Because it is to be expected that in the future an increasingly larger number of vehicles will be equipped for transmitting traffic status messages, significant costs are expected to accrue to the service provider.
For this reason, the problem addressed by the present invention is that of providing a method for the operation of a driver assistance system in a vehicle, the method enabling a more cost-effective provision of an electronic data transmission service.
An additional problem addressed by the present invention is that of providing a method for the operation of a communications infrastructure for detecting and producing road traffic data, the method requiring minimal cost inputs while offering high precision.
An additional problem addressed by the invention is that of providing a computer of a driver assistance system in a vehicle which enables the cost-effective operation of a communication infrastructure for detecting and producing road traffic data.
These problems are addressed by exemplary embodiments of the invention including a method for the operation of a driver assistance system, a method for the operation of a communication infrastructure, and a computer of a driver assistance system.
In a first embodiment, the invention creates a method for the operation of a driver assistance system of a vehicle, particularly of a motor vehicle and/or a commercial vehicle. According to this method, a message produced by a central computer is received by a computer of the vehicle, the message having traffic data as well as a confidence parameter which represents a measure for the reliability of the traffic data. The traffic data contained in the message produced by the central computer has a time point for the message, coordinates defining a certain stretch of road, and additional information. Using this data, the vehicle computer can determine whether the traffic event described in the message lies on a route which is relevant for the vehicle. According to the magnitude of the confidence parameter, the transmission of a traffic status message is directed to the central computer, the message having at least one time stamp and also coordinates of the vehicle.
Evaluation of the confidence parameter contained in the message makes it possible for the vehicle computer to decide whether the transmission of a traffic status message to the central computer, the message relating to a detected traffic event, needs to be carried out or not. By means of the confidence parameter, the central computer of a communication infrastructure can control whether it would like to receive additional traffic status messages for a particular traffic event from traffic participants, i.e. vehicles. If the certainty regarding a detected traffic event is sufficiently large, the central computer can then signal by means of a corresponding confidence parameter that it does not need any further information about this particular event. This means that the central computer is sufficiently ‘sure’ with respect to the reliability of the particular traffic event. On the other hand, if additional information is needed by the central computer for the verification of the traffic event, additional traffic status messages can be indirectly “requested” by means of the suitable confidence parameter. The result is that the number of traffic status messages for particular traffic events can be significantly reduced, whereby the costs associated with the provision of the service, compared to the prior art, can also be decreased.
In one embodiment of the method according to the invention, the vehicle computer checks whether the confidence parameter contained in the message exceeds a prespecified threshold value. If the confidence parameter exceeds the prespecified threshold value, transmission of the traffic status message to the central computer is then suppressed. In contrast, if the confidence parameter lies below the prespecified threshold value, the traffic status message is transmitted to the central computer.
In this context, it is reasonable that the traffic data contained in the message is compared by the vehicle computer to traffic data detected by the vehicle computer, and if a difference is determined, the traffic status message is transmitted to the central computer whether or not the confidence parameter exceeds the prespecified threshold value. The determination of a difference between the traffic data contained in the message and the traffic data detected by the vehicle computer need not be carried out only with respect to a difference in the mathematical sense. This process should be understood much more as the detection of a qualitative difference. Such a qualitative difference is considered to exist when, for example, the traffic data contained in the message of the central computer represents a traffic jam for a particular road segment when no such traffic jam (i.e. a stopping state of the vehicle) can be detected by the moving vehicle in the same road segment. In this case, a traffic status message is transmitted to the central computer regardless of the magnitude of the confidence parameter, such that the central computer can broadcast an updated and corrected message for the relevant road segment.
The technology used for the transmission of the message by the central computer to the vehicle computer, as well as the technology used for the transmission of the traffic status message from the vehicle computer to the central computer, are in principle insignificant for carrying out the method according to the invention. In one embodiment, the message sent by the central computer is received by a vehicle receiver unit designed to receive broadcast messages. In another embodiment, the message sent by the central computer is received by a vehicle receiver unit designed to receive mobile communication messages.
In this case, for example the GSM (Global System for Mobile Communications), UMTS (Universal Mobile Telecommunications Standard) or the GPRS (General Packet Radio Service) standard can be used.
It is further reasonable that the message sent by the central computer is constructed according to a protocol of the TPEG TAP standard (Transport Protocol Experts Group and/or TPEG Automotive Profile). This standard already includes a field for the confidence parameter, which can be used for the method according to the invention. This field is termed “Confidence level”. It is originally intended to give assistance in decision making to a vehicle computer for route planning, regarding when re-planning of the route should be undertaken when a traffic event is detected and reported. For this purpose, this field also represents a parameter which represents a measure for the reliability of the traffic data. However, such a threshold value for modifying the route planning must of course be selected in a different manner from a threshold value for carrying out the method according to the invention.
Particularly, the threshold value lies above an additional threshold value for the confidence parameter if the additional threshold value is used for deciding whether a modification must be undertaken for the route planning determined for the vehicle. It is reasonable that the threshold value is greater than 70%, particularly greater than 75%, and preferably greater than 80%. The threshold value can consequently assume any value between 0 and 1 and/or 0% and 100%. It is also reasonable to design the confidence parameter in the form of a (digital) flag with two values in order to control suppression or transmission of the traffic status message to the central computer.
The invention further comprises a computer program product which can be loaded directly into the internal memory of a digital computer of a vehicle, and which has software code segments which carry out the steps of the described method when the product is running on the vehicle computer.
In a second embodiment, the invention creates a method for the operation of a communication infrastructure for detecting and producing road traffic data.
According to this method, a traffic status message containing at least one time stamp and also coordinates of the vehicle is sent to a central computer by at least one vehicle participating in traffic activity, the message being sent in prespecified intervals and/or upon the appearance of a detected, prespecified event. From the received traffic status messages, the central computer produces a message which has the traffic data and also a confidence parameter which represents a measure for the reliability of the traffic data, and transmits said message to the at least one vehicle. The message produced by the central computer, containing the traffic data and the confidence parameter, is received by a computer of the at least one vehicle. Depending on the magnitude of the confidence parameter, the transmission of an additional traffic status message is directed by the at least one vehicle to the central computer.
In this way, transmission of traffic status messages can be prevented for events which have already been detected with certainty. And as such, costs for the operation of the communication infrastructure can be reduced.
In one embodiment of the method, the computer of a vehicle checks whether the confidence parameter contained in the message exceeds a prespecified threshold value. Transmission of the traffic status message to the central computer is then suppressed if the confidence parameter exceeds the prespecified threshold value. In contrast, the traffic status message is transmitted to the central computer if the confidence parameter is less than the threshold value.
According to an additional embodiment, the traffic data contained in the message is compared by the vehicle computer to traffic data detected by the vehicle computer, and if a difference is determined, the traffic status message is transmitted to the central computer, whether or not the confidence parameter exceeds the prespecified threshold value.
The central computer then broadcasts the message, in the broadcast method, or transmits the same as a dedicated mobile communications message to the at least one vehicle. The transmission can, as described above, be carried out according to the GMS, UMTS, or GPRS standard, for example.
It is reasonable that the central computer transmits the message according to a protocol of the TPEG TAP standard, because this standard already includes a field for the confidence parameter which can be used according to the invention.
In addition, the invention provides that the central computer transmits the message in periodic intervals to the at least one vehicle, and the confidence parameter is adjusted each time to the reliability of the traffic data.
For the determination of the confidence parameter, the central computer does not necessarily have to rely solely on the information received in the traffic status message of the at least one vehicle. The central computer can also incorporate data from sensors (e.g. cameras and induction coils) arranged in stationary positions along a certain segment of traffic into the result of the traffic data and into the confidence parameter. If such a stationary infrastructure is developed and constructed to useful proportions, it may be optionally unnecessary to include traffic status messages from vehicles for a particular road segment. Also by means of this combination, costs can be saved for the traffic status messages.
Finally, the invention comprises a computer of a driver assistance system in a vehicle, particularly in a motor vehicle and/or a commercial vehicle. The computer has a receiving unit for receiving a message produced by a central computer, the message having traffic data and a confidence parameter which represents a measure for the reliability of the traffic data. The computer also has a control unit for directing the transmission of a traffic status message, having at least one time stamp as well as coordinates of the vehicle, to the central computer according to a magnitude of the confidence parameter.
Moreover, the computer is designed to carry out the described method. A computer according to the invention has the same advantages as the method described above.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.